ATLANTA — There is a risk that the pathogens that accumulate on kitchen towels can cause food poisoning, but how much of a risk depends on several factors, including family size, diet type and what exactly the towels are used for, researchers reported here.
“Our study demonstrates that the family composition and hygienic practices in the kitchen affected the microbial load and microbial profile of kitchen towels,” Susheela D. Biranjia-Hurdoyal, PhD, a senior lecturer at the University of Mauritius, said in a press release.
In a previous study of 53 households, Biranjia-Hurdoyal and another colleague found that kitchen tables were an important source of pathogens that can cause foodborne diseases, and they also discouraged the use of plastic covers and multipurpose sponges and towels because they could potentially increase the number of bacteria that cause illness.
In their latest study, the researchers provided 100 kitchen towels to families to use for 1 month. Afterward, they cultured bacteria from the towels and identified them using standard biochemical tests. They also administered questionnaires to participants to identify risk factors for contamination.
They found bacterial growth in almost half (49%) of the kitchen towels, and the number of bacteria significantly increased with bigger families, extended families and the presence of children. Multipurpose towels — those used for wiping utensils, drying hands, holding hot utensils and wiping surfaces, for example — had significantly higher colony-forming units (CFUs) than single-use towels. Also, humid towels had higher CFUs than dry towels, as did cotton towels compared with nylon towels or towels made from both materials.
Out of the 49 towels that tested positive for bacteria, 36.7% grew coliforms, 36.7% grew Enterococcus spp., 30.6% grew Pseudomonas spp., 28.6% grew Bacillus spp., 14.3% grew S. aureus, 4.1% grew Proteus spp., and 2% grew coagulase-negative staphylococci.
Notably, Staphylococcus aureus was isolated at a higher rate from the towels of families of lower socioeconomic status (P < .05). The reason, Biranjia-Hurdoyal said, is that people in this socioeconomic group tend to have bigger families, extended families and children in the house — all risk factors identified in the study.
Diet also was found to be an important factor, the researchers said. Coliforms and S. aureus were detected at a significantly higher prevalence among families on nonvegetarian diets, whereas a higher prevalence of Enterococcus spp. was isolated from the kitchen towels belonging to vegetarian families.
Biranjia-Hurdoyal told Infectious Disease News that some respondents may have overstated how regularly they washed their towels, and so the researchers were unable to draw any conclusions about how long a towel could go unwashed before it is unsafe to use.
“If you have children at home, if you have elderly people, and if you have humid towels and a habit of [using towels for multiple purposes], you need to wash them whenever you use them,” she said. – by John Schoen
Biranjia-Hurdoyal S, et al. AES LB11. Presented at: ASM Microbe; June 7-11, 2018; Atlanta.
Biranjia-Hurdoyal S, et al. Can J Infect Dis Med Microbiol. 2016;doi:10.1155/2016/3574149.
Disclosures: The researchers report no relevant financial disclosures.